1. The Field of the Invention
The present invention relates to arched culverts, methods of manufacture, and related components thereof.
2. The Relevant Technology
Arched culverts are used for forming large volume water pathways that cover and direct a flow of water. For example, arched culverts are commonly used for capturing and directly all or a portion of the water from streams or small rivers, transporting runoff water through large cities, and forming bridges under which water travels.
Depicted in FIG. 1 is a conventional arched culvert 1 bounding a water pathway 7. Arched culvert 1 comprises a concrete slab 2 having a top surface 3 with a pair of spaced apart keyways 4A and 4B extending along the length thereof. A plurality of arches 5A-5C are positioned end-to-end on top surface 3 of slab 2. More specifically, opposing ends 6A and 6B of each arch 5A-5C are received within keyways 4A and 4B, respectively. A grout is filled into any space within keyways 4A and 4B not occupied by ends 6A and 6B of arches 5A-5C.
The assembled configuration of arched culvert 1 forms water pathway 7 that is bounded between the interior surface of arches 5A-5C and top surface 3 of slab 2. The length of slab 2 and the number of arches used depends on the desired length for arched culvert 1. Arched culvert 1 is formed below ground surface so that when completed, a backfill material is deposited over the top of arched culvert 1, thereby forming an underground tunnel on which roads and/or some other structures can be built.
Although conventional arched culverts are used extensively for transporting water, the conventional systems and methods of manufacture have significant shortcomings. For example, the only structural engagement between arches 5A-5C and slab 2 is the freely disposed placement of the ends 6A and 6B of the arches 5A-5C within keyways 4A and 4B. That is, keyways 4A and 4B are intended to prevent lateral movement of arches 5 relative to slab 2. However, slab 2 is formed as a poured-in-place concrete slab. Forming keyways 4A and 4B along the length of slab 2 substantially increases the time, effort, and cost to form slab 2. Furthermore, the placement of keyways 4A and 4B must be made at a fairly close tolerance so that ends 6A and 6B of arches 5A-5C can be received therein. Any misalignment of keyways 4A and 4B results in substantial labor and effort to reform slab 2 for receiving the arches.
Even if arches 5A-5C are properly received within keyways 4A and 4B, because there is no structural fastener that positively secures arches 5A-5C to slab 2, it is not uncommon for one or more of arches 5A-5C to become laterally displaced relative to slab 2 as a result the ends of arches 5A-5C moving out of keyways 4A and 4B. This can occur when backfill is applied against arches 5A-5C or when fluid pressures, such as those caused by flood waters, are applied against the interior surface of arches 5A-5C. Furthermore, to facilitate proper longitudinal alignment between adjacent arches 5A-5C, it is often necessary to upwardly shim one or more ends of arches 5A-5C. By upwardly shimming the walls, however, the walls are partially raised within or out of channel 4A and/or 4B, thereby further decreasing resistance to lateral displacement. Any lateral displacement of arches 5A-5C can result in erosion of the surrounding soil and can potentially lead to failure of one or more of arches 5A-5C.
In addition to having low shear resistance, because there is no positive structural connection between arches 5A-5C and slab 2, arches 5A-5C have minimal resistance to applied moment or torsional forces. As a result, arched culvert 1 has greater susceptibility to failure or at least displacement when subject to a variety of different loads.
Accordingly, what are needed in the art are arched culverts and methods of manufacture that eliminate or minimize all or some of the above shortcomings.